The durability of polymer compo sites is of crucial impor tance

no matter in scient ific and techno logical point of view. Many involved problems are little understo od and need thoroug hresearch. First is the stability of polymer it self and the key factors. The second is the interaction between inorganic fillers and polymermatrices and its effect on aging behavior of polymer composites. The effect of surface treatments of inorganic fillers on the interaction is also concerned. In addition

the heterogeneity nature of photo-oxidationreaction and the degradation distribution in the composites need careful consideration. In this paper

the current progress in thepho to-oxidation degradation behavior and mechanism of polyolefin composites have been reviewed

with an emphasis on HDPE filled with common mine ralfillers

PE and PP filled with nano fillers such as Al

2

O

3

SiO

2

CaCO

3

TiO

2

and ZnO.